Apparatus for oiling sheet metal stock

ABSTRACT

Chamber-defining means define a chamber, a sealing inlet to said chamber and a sealing outlet from said chamber. Stock-feeding means are operable to feed sheet metal stock through said inlet, chamber, and outlet along a predetermined path. A plurality of nozzles open in said chamber and are spaced apart transversely to said path and directed toward said path and operable to discharge an oil-air mixture toward said path. A suction conduit is connected to said chamber. A compressor is connected between said suction conduit and a closed container and operable to such surplus oil-air mixture from said chamber and to deliver compressed air and oil to said container so as to form in said container a body of oil and a body of compressed air above said body of oil. An oil conduit is connected to said nozzles and to said container to communicate with said body of oil. A compressed air conduit is connected to said nozzles and to said container to communicate with said body of compressed air.

United States Patent Glanzer 1 June 5, 1973 54] APPARATUS FOR OILINGSHEET 3,594,228 7 1971 Mock ..118/326 x METAL STOCK [75] Inventor:Stefan Glanzer, Linz, Austria Pnmary Examiner-John McIntoshAttorney-Kurt Kelman [73] Assignee: Vereinigte Osterreichische EisenundStahlwerke Aktiengesellschaft, [57] ABSTRACT Ausma Chamber-definingmeans define a chamber, a sealing [22] Filed: Sept. 28, 1971 inlet tosaid chamber and a sealing outlet from said Appl. No: 184,489

Foreign Application Priority Data Oct. 19, 1970 Austria ..9378

U.S. Cl. ..118/50, 118/316, 118/325, 118/326, 118/7 Int. Cl......B05c5/00, B050 11/115, BOSc 11/16 Field of Search ..118/315, 316, 326,118/50, 50.1, 8, 7, 325; 134/103, 109, 57 R chamber. Stock-feeding meansare operable to feed sheet metal stock through said inlet, chamber, andoutlet along a predetermined path. A plurality of nozzles open in saidchamber and are spaced apart transversely to said path and directedtoward said path and operable to discharge an oil-air mixture towardsaid path. A suction conduit is connected to said chamber. A compressoris connected between said suction conduit and a closed container andoperable to such surplus oil-air mixture from said chamber and todeliver compressed air and oil to said container so as to form in saidcontainer a body of oil and a body of compressed air above said body ofoil. An oil conduit is connected 'to said nozzles and to said containerto communicate with said body of oil. A compressed air conduit isconnected to said nozzles and to said container to communicate with saidbody of compressed air.

6 Claims, 1 Drawing Figure APPARATUS FOR OILING SHEET METAL STOCK Thisinvention relates to apparatus for oiling sheet metal stock in the formof strip, plate or sheet, which apparatus comprises a closed chamber,which is provided with a sealing inlet and a sealing outlet for thesheet metal stock, and a plurality of nozzles, which are disposed in thechamber and spaced apart transversely to. the direction of travel of thesheet metal stock and connected to an oil conduit and a compressed airconduit and serve to blow an oil-air mixture onto the sheet metal stock,a suction conduit for the surplus oil-air mixture being provided andconnecting the chamber to a suction device.

The buyers of sheet metal stock in the form of strip, plate or sheetimpose rigid specifications as regards the oiling of such sheet metalstock because the surface should be provided with a lubricant film whichis as uniform as possible. Known apparatus for oiling sheet metal stockin the form of strip, plate or sheet comprise dripping taps, nozzles orthe like which are spaced apart transversely to the direction of travelof the sheet metal stock and supply the oil from above to the travellingstock. In these arrangements, the oil is applied to felt rollers, whichengage the sheet metal stock. The rapid wear of the felt rollers is agreat disadvantage of these arrangements and requires that the feltrollers must be frequently dressed and must be replaced after a certainlifetime. This results in high operating costs. Difficulties arise alsoin the control of the supply of oil and in the adjustment thereof inresponse to changes in the speed of travel. Owing to these difficulties,such apparatus have no longer been used in more recent plants.

In another known apparatus for oiling strip metal, the difficulties areavoided substantially in that the oil is sprayed to an applicator roll,which contacts the moving strip and is adapted to be driven insynchronism therewith. The spraying device is operated with intervals oftime, which depend on the speed of the strip. The spraying period isconstant so that oil in an amount which depends on the speed of travelof the metal strip is sprayed onto the applicator roll and transferredby the latter onto the strip. The applicator rolls of such apparatusconsist again of felt rolls, which are not satisfactory, as has beenmentioned. Besides, the atomization of the oil gives rise todifficulties and it has been attempted to avoid such difficulties by theuse of injection pumps, such as are employed in engines of motorvehicles. Small air bubbles trapped in the oil result in an accumulationof air in the injection pumps so that the latter must be repeatedlyvented.

All known apparatus which have been described hereinbefore have thedisadvantage of involving a very high consumption of oil but failing toapply the oil to the metal strip as uniformly as desired.

Another apparatus has been disclosed, which comprises nozzles that aredisposed in a closed chamber and blow an oil-air mixture onto the stripmetal moving through the chamber and through inlet and outlet openingsthereof. This results in an oil film which is as uniform as desired. Theapparatus has the disadvantage that the resulting oil mist must besucked from the chamber and the oil must be separated from the air byfilter systems, which are expensive and complicated. Because the oilcannot be completely separated from the air, the air blown into theatmosphere still contains a considerable proportion of oil so that theopening costs of the plant are much increased.

It is an object of the invention to eliminate these disadvantages and toprovide for the oiling of sheet metal stock in the form of strip, plateor sheet an apparatus which ensures an application of a uniform oillayer to the sheet metal with simple means and without an excessivelyhigh consumption of oil and compressed air.

In an apparatus of the kind defined first hereinbefore, theabove-mentioned object is accomplished by the invention essentially inthat the suction device consists of a compressor, a pressure conduit isconnected to the compressor and leads to a closed container, which ispartly filled with oil, the oil conduit leading to the nozzles isconnected to said container at a point below the oil level therein andthe compressed air conduit leading to the nozzles is connected to thecontainer above the oil level therein. Hence, the invention provides asubstantially closed cycle, which enables a return of the sucked-offoil-air mixture into the container, which serves as an oil reservoir anda compressed air reservoir. The oil-air mixture which has beencompressed in the compressor flows through the pressure conduit into thecontainer, in which a major portion of the mixture is segregated and theoil can fill only part of the container. The pressure which is generatedby the compressor is transmitted to the container above the oil leveland forces the oil out of the container through the oil conduit leadingto the nozzles, which are supplied with compressed air through thecompressed air conduit from the container serving also as a compressedair reservoir. The nozzles blow the oil onto the surface of the sheetmetal to form a uniform film thereon. The surplus oil-air mixture isdischarged in the suction conduit. To ensure that a suitable supply ofoil will be maintained in the container and that the oil blown onto thesheet metal stock will be replaced, a float is provided, which by meansof a controller provides for an automatic control of the supply of freshoil into the container.

Because a relatively low pressure is sufficient for the operation of thenozzles, the oil conduit and the compressed air conduit preferablyincorporate respective pressure-reducing valves, by which the operatingpressure can be adjusted independently of the compressor.

In another embodiment of the invention, a by-pass conduit incorporatinga pressure relief valve is connected between the pressure conduit andthe suction conduit and by-passes the compressor. When operating at aconstant speed, the rate of air delivered by the compressor into thecontainer may exceed the rate at which air is supplied from thecontainer to the nozzles. This would result in an excessive pressure inthe pressure conduit. When the pressure in the pressure conduit reachesa predetermined value, the pressure-relief valve in the by-pass conduitopens so that the compressor is short-circuited.

The accompanying drawing is a diagrammatic sectional view showing anembodiment of the invention by way of example.

A chamber 1 defined by two housing parts contains a plurality of nozzles2, which are spaced apart transversely to the direction of travel of thestrip metal 3 and disposed above and below the latter. The strip 3extends through the chamber 1 and through a sealing inlet and a sealingoutlet thereof and is moved by two v pairs of rollers. One pair ofrollers are designated 4 and disposed behind the plane of the drawing.The other pair of rollers are disposed before the plane of the drawing.These feed rollers are adjustable in height for adjustment to sheetmetal stock differing in thickness. A common oil conduit 5 and a commoncompressed air conduit 6 lead to the nozzles 2. The oil conduit and thecompressed air conduit incorporate respective pressure-reducing valves 7so that the desired pressure for blowing an oil-air mixture onto thestrip steel 3 can be adjusted independently of the compression by acompressor 8.

A suction conduit 9 extends from the chamber 1 to the compressor 8,which in the present example is an axial compressor. The compressor 8 isconnected by a pressure conduit 10 to a container 11, which is partlyfilled with oil. The pressure conduit 10 incorporates a check valve 12.The container 11 serves as a compressed air reservoir and as an oilreservoir.

The surplus oil-air mixture is withdrawn from the chamber 1 through thesuction conduit 9 by the compressor 8, which is driven by a motor 13 andcompresses the mixture and delivers it through the pressure conduit 10to the container 11. The oil which separates from the oil mist as it iscompressed flows also through the pressure conduit 10 into the container11. The compressed air in the pressure zone 14 of the container 11 ismaintained under a constant pressure because the oil level isautomatically controlled by means of a float 15, which operates anelectric switch 17, which by a controller, not shown, controls a valve18 in an oil supply conduit. The oil supply conduit 16 is connected toan oil supply tank, to which a drain conduit 19 is connected, whichserves to return the oil that has collected at the bottom of the chamber1 during the operation of the oiling apparatus. Upon a drop of the oillevel in the container 11, the float 15, the switch 17 and the controldevice cause the valve 18 to open so that fresh oil can flow from thesupply tank through the conduit 16 into the container 11. When thedesired oil level has been reached, the valve 18 is closed to block theconduit 16.

Owing to the operation of the compressor, a pressure of about 5-6 kg/cmabove atmospheric pressure is maintained in the pressure zone 14 andforces the oil through a fine filter 20 into the oil conduit 5. The oilpressure desired for the operation of the nozzles can be adjusted bymeans of the pressure-reducing valve 7. At the same time, compressed airis supplied from the pressure zone 14 through the compressed air conduit6 and the adjustable pressure-reducing valve 7 to the nozzles 2. Thelast-mentioned pressure-reducing valve 7 serves to reduce the airpressure to the desired operating pressure. The nozzles 2 result in afine atomization of the oil and blow it onto the strip 3, which iscontinuously moved through the chamber 1. The operation of the nozzlesresults in the production of an oil mist at a rate which depends on therate at which compressed air is supplied. By the axial compressor 8, thesurplus oil-air mixture is sucked off through the suction conduit 9 andcompressed to about 5-6 kg/cm?.

Operating at a constant speed, the compressor 8 delivers air into thepressure zone 14 of the container 11 at a rate which is higher than therate at which air is supplied from the pressure zone through the conduit6 to the nozzles 2. This results in an excessive pressure in thepressure conduit 10. When the pressure in the pressure conduit 10 hasreached a predetermined value, a pressure relief valve 21 opens, whichis incorporated in a by-pass conduit 22, which by-passes the compressor10 and is connected between the pressure conduit 10 and the suctionconduit 9. When the pressure relief valve 21 is open, the compressor 8is short-circuited. It is desirable to maintain in the chamber apressure which is slightly subatmospheric so that the oil mist cannotescape from the chamber 1, e.g., at the joint between the two parts ofthe housing defining the chamber. The subatmospheric pressure producedby the compressor causes a small amount of fresh air to be sucked intothe chamber 1 so that there will be no def ciency of air during theoperation of the oiling apparatus.

It is apparent that the apparatus provided by the invention and servingto oil sheet metal products in the form of strip, plate or sheet can beoperated with a minimum oil consumption and requires only a low power toproduce the continuously circulating compressed air. Specialrequirements are not involved in the maintenance and control of theentire plant. For these reasons, the apparatus can fully accomplish theobject underlying the invention.

What is claimed is:

1. Apparatus for oiling sheet metal stock, which compriseschamber-defining means defining a chamber, a sealing inlet to saidchamber, and a sealing outlet from said chamber,

stock-feeding means operable to feed sheet metal stock through saidinlet, chamber, and outlet along a predetermined path,

a plurality of nozzles opening in said chamber and spaced aparttransversely to said path and directed toward said path and operable todischarge an oilair mixture toward said path,

a suction conduit connected to said chamber,

a container,

a compressor connected between said suction conduit and said containerand operable to suck surplus oil-air mixture from said chamber and todeliver compressed air and oil to said container so as to form in saidcontainer a body of oil and a body of compressed air above said body ofoil,

an oil conduit connected to said nozzles and to said container tocommunicate with said body of oil, and

a compressed air conduit connected to said nozzles and to said containerto communicate with said body of compressed air.

2. Apparatus as set forth in claim 1, in which said stock-feeding meansare operable to feed sheet metal stock in strip form.

3. Apparatus as set forth in claim 1, in which said stock-feeding meansare operable to feed sheet metal stock in the form of discrete elements.

4. Apparatus as set forth in claim 1, which comprises means formaintaining a predetermined level of oil in said container.

5. Apparatus as set forth in claim 1, which comprises apressure-reducing valve incorporated in said oil conduit and apressure-reducing valve incorporated in said compressed air conduit.

6. Apparatus as set forth in claim 1, which comprises a by-pass conduitconnected between said pressure conduit and said suction conduit toby-pass said compressor and a pressure relief valve incorporated in saidby-pass conduit.

l i I t

1. Apparatus for oiling sheet metal stock, which compriseschamber-defining means defining a chamber, a sealing inlet to saidchamber, and a sealing outlet from said chamber, stock-feeding meansoperable to feed sheet metal stock through said inlet, chamber, andoutlet along a predetermined path, a plurality of nozzles opening insaid chamber and spaced apart transversely to said path and directedtoward said path and operable to discharge an oil-air mixture towardsaid path, a suction conduit connected to said chamber, a container, acompressor connected between said suction conduit and said container andoperable to suck surplus oil-air mixture from said chamber and todeliver compressed air and oil to said container so as to form in saidcontainer a body of oil and a body of compressed air above said body ofoil, an oil conduit connected to said nozzles and to said container tocommunicate with said body of oil, and a compressed air conduitconnected to said nozzles and to said container to communicate with saidbody of compressed air.
 2. Apparatus as set forth in claim 1, in whichsaid stock-feeding means are operable to feed sheet metal stock in stripform.
 3. Apparatus as set forth in claim 1, in which said stock-feedingmeans are operable to feed sheet metal stock in the form of discreteelements.
 4. Apparatus as set forth in claim 1, which comprises meansfor maintaining a predetermined level of oil in said container. 5.Apparatus as set forth in claim 1, which comprises a pressure-reducingvalve incorporated in said oil conduit and a pressure-reducing valveincorporated in said compressed air conduit.
 6. Apparatus as set forthin claim 1, which comprises a by-pass conduit connected between saidpressure conduit and said suction conduit to by-pass said compressor anda pressure relief valve incorporated in said by-pass conduit.